Yes. Our build system produces complete packages of the game, and I'm a platform engineer - so within one day I'll often download a PC package, one for PS5, Xbox, Switch, Android and iOS, depending on what kind of thing I'm working on. So yes all of them are completely unique. Or I'm looking at builds made for different backends. Or I pushed a preflight for overnight cooking/building, it takes about 8 hours - so I need to download the output to see if it works across different systems.
Because I would have expected for game development that it would be rare for majority of the large assets (art, textures, 3d meshes, video, sound, music) to change multiple times per day, so - to me - sounds like would perfectly suit a differential/incremental sync protocol, rather than treating everything as a large packed blob. At least that was the case for the game development I did.
And generally - you are correct. But builds made for specific platforms have all of their assets "cooked" for that platform - so textures shipping on PS5 are not in the same format as textures shipping on the Switch, even though they were both made from the same original reference file.